Telegraph-transmitter.



T. J. DUNN. TELEGRAPH TRANSMITTER. APPLICATION FILED DEO.31. 1908.

Patented May Q5, 1909;

WITNESSES:

THOMAS J. DUNN, OF JERSEY CITY, NEW JERSEY, I

TE IEGRAPH-TRANSMITTER.

Specification of iletters Patent.

Patented May 5255, 113965).

Application'filed Decemberfil, 1908. Serial No. 470,236.

To all wlro'mit may concern:

Be it known that l, TnoMAs J. DUNN, a citizen ol'the United States. residing at Jerscy-(Jity, in the county of lludson and State oiNew Jersey, have invented certain new and uselul .linn'oveinents in 'lelegraphic 'lransrnitters, which the following is-a full,

clear, and exact description.

.ThlS invention relates to so-culled semiautomatic telegraph. keys, and has for its object to provide a siniplcnnd compact instrument which can be manufactured at low cost and which shall wil hal be thoroughly reliable in operation.

To this and other ends the invention consists-in the novel features of construction and combinations of elements hereinafter described, and more particularly set forth in the claims.

, A convenient and effective embodiment of my invention is illustrated in the annexed drawing, and referring now thereto, Figure l similar material.

is lan view with the casing in section,

showing the operative parts. Fig. 2 is a Fig. 3 is a section on line 3 .3. Fig. l is a detail View of the (ingerkey end of the instrumcnt, with one of the linger keys reluovcd.

The opcriitivi-l parts oi the. device are inmintul on a base A, preferably rectangular in form and made oi cast metal, heavy enough to rest firmly on a table or desk, provided with feet a of soft rubber or other Around the base is an upwardly extending flange A within which fits the inclosing casing or cover hereinafter described. At one corner of the base is a short upright post 13 having 'a. downwardly extending slot in its top in which is securely fixed a horizontally extending bla les.pring i, carrying at its forward end a still rod (f. Onthc rod is a slidahlc wclghlc provided Witha sct-scrcw c by which it can be firmly secured in adjusted position. it will now be evident that if the. rod or vibrator C be drawn to one. side, thus slightly flexing the spring (1, and then be released, the vibrator will oscillate rapidly under the influence of its own momentum and the resiliency of the blade s wring.

Slide 1y mounted on the vibrator is a collar C provided with a set-screw c by which it maybe secured in a'ljusted position, and carrying alight flexible contact spring C said contact spring being U-shaped, as shown, and fastened to the collar by one end. The

opposite end of the contact spring lies adjacent to a fixed contact D, in the form of a screw working in a short vertical 0st d so as to be adjusted toward and horn the spring. It will now be seen that as the vibrator oscillates the contact spring will at guided thereby in their vertical movements.

The plungers are tubular and at their upper ends are provided with longitudinal slots to receive feathers i on the stems of the finger buttons f, g, h, when said stems are mscrtod in the plungers.

The center plunger G carries a cam mem' ber G having an inclined cam sulface or edge 9 arranged to bear on the underside of the. vibrator C when the said plunger and cam member are in their uppermost positions, the action of the cam member being to hold the vibrator to the right (asviewed in Fig. 3) ol its central position, with. the spring 0 slightly flexed. It will therefore be seen that on depression of the plunger G the cam member will be'carried out of engagement with the vibrator, whereupon the tension of spring C will throw the vibrator to the other side,

after which it continues to oscillate b its own momentum and the resiliency o the spring, as previously described:

Plunger H carries a switchfinger 71- adapted to engage the underside otthe elevated end of a terminal arm K, the other end of which extends under the plunger ll, said terminal arin being insulated. from the base -A. In electrical connection with the arm,

and directly under the plunger F, is a contact stop L, so that when said plunger is do pressed it will be brought into electrical contact with the stop.

Adjacent to the post B, and insulated from the base A, is a binding post J, and leading therefrom to the post (i, which, it will be remembered, carries the contact screw l), is a conducting strip 7''. The latter also extends into electrical connection with the switch terminal K. Adjacent to the binding post J is another binding post, M, electrical connection with the base A, and to these binr g osts the conductors N, O, are connected,

ceding to the telegraph line.-

The 0 eration of the instrument will now be reedi y understood. if the operator desires to send a dash, or prolonged impulse of i current 'he first opens the circuit by, depress ing key h and partially rotating it to carry the finger 7L2 from under the terminal arm K. Upon release of the key the finger 71- clears the arm, leaving the circuit open. He then depresses the dash lzeyf, thereby cs 'eblish mg the circuit as follows: wire N,,binding 5 post M, base A, bracket E, plunger F, contact stop L, conducting strip 7', binding post J and Wire 0. Upon release of the hey the plunger rises under the influence of springf, Whereu on the circuit is broken the stop L. If dots, or short impulses of current are to be sent, the key 9 is depressed, withdraw ing the cam memberG from nent with the vibrator and causing the latter to oscillate as previously described. l 'hen the contact spring C strikes the screw D the circuit is established as follows: wire N, inding post M, base A, post 2, spring C, vibrator 0, spring C screw D, post cond, sting .strip 1, binding post 5, and wire 0. The vibrator immediately swings outward, u

drawing the spring c from contact l screW'D and thereby breaking the circuit, which, however is reestablished by the succeeding inward swing of the vibrator. in this way the circuit is closed and broken in rapid succession, causing o succession of short: impulses, or dots, to be sent over the line. l When the desired number of dots have been sent, which the operator escertuins by 40 counting, the (lot key, 9'', is released, whereupon the cam member G is again brought into engagement with the vibrator, arresting it and carrying it out to its inopcrs 'tive posh tion' Thus by pro )er manipulation of the dot and dash keys, tr e dots and dashes oi the Morse code can be sent in any number and in any order of succession.

The rate at which the dots are sent is determincd by the position ol' the weight- 0 on the vibrator, the rate being increased by shifting the weight toward the supporting spring C, and vice verso, as will be readily understood. I The finger buttons bear on their tops suitable characters to indicate their functions. Thus on button appears the letter S, indicatin switch, the letter being so orrunge d t at when the switch is closed the letter will stand in upright position, as shown 60 Fig. 4. This position of the letter is as 'sure d by the fact that the button cannot be inserted in the plunger H unless the feather on the button stem is in register with the slot in the lunger. Button 9 beers u dot, as 5 shown 1n Fig. 4, to indicate that-it is the key, and buttonf hours a dash, not shown, to indioete that it is the dash key.

Users of prior keys of the semi-automatic type have sullcred greet annoyance through tempering no. the adjustments of the device oy meddleson're persons. Such persons, seeing the key unused on the operators table or desk, and ettrucled by itsnovelty, stop to examine or test it, and are apt to attempt to readjust it. "The consequence is that when the o ere-tor tries to use the instrument again 1e finds the adjustments, to whicn he has been accustomed, have been disturbed,

and. he is therefore put to considerable, trouble to restore the device to theproper condition for the most effective use. 1 their fore propose to make the operative parts and the :uljusting members inaccessible to the casual pssserby and for that purpose 1. provide e rectangular casing or cover P, to inclose the parts, permitting only the linger keys to project through the cover, through suitable openings therein. To hold the cover or casing securely in place, yet permit removul of the same when d ired, the casing is provided with eyes p, Fig. l, projecting through apertures in the base A, below Whicn they are engaged by suitable books a (shown in dotted lines in Fig. 1) ,n-ivotcd to the underside of the base. sit the rear end of'the cover is on opening, indicntcdin dotted lines 2" in Fig. 1, for the passage of the lead O The cover itself is flat, and the ,cntirc do ice is fist and compact enough to enable it to he slipped into the pocket, so that the owner can carry it about with him instead of leaving it on his desk where it may be tempered with by the curious.

The instrument herein specifically described is merely the preferred embodiment of the invention, and may be modified in various ways without departure from the proper spirit and scope of the invention as defined by the appended claims.

l'l' hst 1 claim is:

l. in s telegraph transmitter, in combinw tion base, a. horizontally arranged vibrator supported thereon, a vertically reciprocatoiy plu ngcr lmving means normally engaging the vibrator and adopted on the downward movement of the plunger to release the vibrator, and o pair of-electrical contacts one carried by the vibrator and the other fixed in the path of the first, as set forth,

2. In a telegraph trunsn'litter, in combines tion, a. horizontally arranged vibrator, a blade-spring supporting the some by one end, s contact spring carried by the vibrator, s. lined contact in the path of the contact spring, a vertically rcciprocstory plunger adjacent to the free end of the vibrator, and as corn member carried by said plunger adopts ed to engage the vibrator wlj-en the plunger is in its raised position, as sct forth.

3. In a, telegrephtmnsmitter, 1n combine-- vibrator and the said fixed contacts, as set 6. In a telegraph transmitter, in combination, a casing, automatic means Within the easing for sending shortcurrent impulses in rapid succession over a telegraph line, a vertically and in electrical connection with the vibrator, a dash contact adapted to be engaged by the second plunger when the same is dei pressed, a fixed contact in the path of the dot contact carried by the vibrator, and

means for connecting thedash contact and said fixed contact with the other terminal of the telegraph. circuit, as set forth.

4.. In a telegraph transmitter, in combination, a horizontally arranged vibrator, a

spring supporting the same by one end, a bracket extending transversely of the vrbra- 5 tor at its" free end, a plunger mounted-to reciprocate vertically in said bracket, a cam member carried by said plunger. and nor- 5 mally engaging the vibrator, a second plungcr mounted to reciprocate vertically in said bracket, a dash contact in the path of the second plunger, a dot-contact carried by the vibrator, and a fixed contact in the path. of

the said dot-contact, said daslr-c mtact and fixed contact being electrically connected, as

set forth.

In a telegraph transmitter, in combina- 1 tion, a horizontally arranged vibrator, a dot l i pinge upon the inc osed dashcontaet fo'rsendcontact in the path of the movable dot-contact, a series of three vertically reciprocatory contact carried by the vibrator, a fixed dotplungers extending transversely of the vibrator, means associated with one of said plungers for controlling the vibrator, a fixed dash contact in the path ol' another ol' the plungcrs and in electrical connect ion with the said fixed contact, and a switch actuated by 1 the third plunger and in circuit with the i reciprocatory plunger controlling said means and extending outside the casing in position for actuation by the finger, a vertically reciprocatory daslrplunger extending outside of said casing,,means inside the casing cooperating with said dash-plunger for sending L prolonged impulses over th e telegraph line when said dash plunger is depressed, a switch-plunger extending outside of the. easing, and a switch inside the casing, operatet by the switch plungerfor closing and opening the telegraph circuit at will, as set forth.

7. In a telegraph transmitter, a base, a horizontally arranged vibrator supported on the base, means cooperating with the vibra tor for sending short current impulses or dots in rapid succession over a telegraphline, a dash-contact mountedon the base and electrically connected with said means, an inclosing casing detachably secured on the base, a vertically reciprocatory plunger to be actuated by the linger of the operator and extending into the casing,.means carried by the said plunger within the casing for controlling the vibrator, and a vertically reciprocatory plunger adapted to be actuatedby the linger of the operator and adapted to 1ming prolonged current impulses or dashes.

"rnonils J. nuns;

Witnesses:

M. l1AVVS0N DYER, S. S. I)UN-HAM. 

